Search Results (269)

Measurement of material thermodynamic parameters plays a crucial role in understanding the interactions between host materials and guest species. Therefore, developing a general-purpose system for thermodynamic parameter measurement is of great significance. In this work, a complete gas–solid interface thermodynamic parameter measurement platform was developed based on isothermal adsorption and a resonant microcantilever testing platform. Unlike conventional adsorption measurement systems that rely on manual, multi-cycle adsorption–desorption processes, the proposed platform integrates an automated hardware–software architecture together with a stepwise concentration-gradient protocol and on-chip thermal desorption, enabling continuous and efficient acquisition of adsorption isotherms. The study includes: (i) construction of an improved thermodynamic parameter extraction model based on the Sips model, (ii) development of an integrated resonant microcantilever control and acquisition module using a modified Fourier algorithm, and (iii) implementation of an automated testing and data analysis software framework developed in LabVIEW based on the Queued Message Handler (QMH) architecture. The system was validated from both hardware performance and material testing perspectives using CO₂ adsorption on H-SSZ-13 as a representative case. The results show that the system achieves a maximum sampling rate of 10,000 pts (points per second), with minimum root-mean-square (RMS) noise levels of 0.0083 Hz for frequency and 0.0109 °C for temperature. The PID temperature-control settling time (0.1%) is 24.9 ms, and the frequency-response settling time (0.01%) is 9.6 ms. Thermodynamic parameters including entropy change (ΔS), enthalpy change (ΔH), and Gibbs free energy change (ΔG) were successfully extracted during CO₂ adsorption at 294.15 K under different relative uptakes. Reproducibility was verified across three independent samples, yielding a standard deviation of 9.1 J·mol⁻¹ for ΔS at 2% relative uptake and relative standard deviations of 6.85% and 8.12% for ΔH and ΔG, respectively. These results demonstrate that the proposed thermodynamic measurement platform features a simple architecture, superior performance, and high reproducibility in gas–solid interface thermodynamic studies, showing strong potential for future commercialization. Full article

Ionotropic alginate-based hydrogelation by divalent metal interaction has been employed to study the effect that different types of ions might have on gel formation. In this regard, EPR and IR spectroscopies, as well as rheology techniques, have been used to evaluate the influence of divalent cations on gel formation, and at the same time to assess host–guest interactions. Alginate was functionalized with TEMPO moieties; therefore, TEMPO-alginate system was taken as a reference. The novelty of this study consists of using a mixture of adamantyl-TEMPO-functionalized alginate and β-cyclodextrin linked through 1,3-diaminopropane to assess the host–guest interactions in functionalized gels. The properties of divalent cations considered in this study (Ba²⁺, Ca²⁺, Sr²⁺, Zn²⁺) were proven by changes in spectral parameters of paramagnetic moieties, while the viscoelastic moduli as functions of shear strain and frequency were evaluated through rheology measurements. Overall, the information obtained from these investigations has shown that the properties of the alginate gels are influenced both by the type of divalent cation used for complexation and by the host–guest interactions. The results show that the type of the cation significantly affects gel strength; therefore, Ba²⁺ forms the strongest gel, while Zn²⁺ the least resistant. Additionally, a high immobilization of the spin-labeled probes has been obtained by the addition of tosylated β-cyclodextrin in the alginate gel network containing Ba²⁺ ions. Full article

Since the first synthetic macrocyclic receptors were shown to bind ions selectively, supramolecular host–guest chemistry has enabled the translation of molecular recognition events into physical signals. Early coupling of such receptors to ion-sensitive field-effect transistors established a bridge between supramolecular chemistry and solid-state electronics. Today, this bridge is rebuilt in iontronics, where ions carry information through nanoconfined media and ionic transport becomes highly sensitive to electrostatic gradients, surface charge, and surface molecular interactions. As a result, ionic flux can serve as an efficient transduction mechanism that responds precisely, reversibly, and rapidly to changes in the chemical environment. Within this regime, host–guest chemistry offers a powerful means to exert direct control over ionic behavior, allowing molecular recognition to modulate conductance, rectification, and ion selectivity, thereby conferring practical function to nanofluidic systems. This review highlights systems in which host molecules act as chemical actuators that modulate nanochannel surface chemistry, thereby regulating ionic flux and enabling reversible, tunable, and stimulus-responsive behaviors. We survey architectures in which crown ethers, calixcrowns, pillararenes, and related hosts are integrated into solid-state nanochannels, emphasizing representative achievements such as biological-level Na⁺/K⁺ selectivity in crown ether-based systems and nanomolar-level detection of ions using calixcrowns- and pillararene-functionalized nanochannels. Finally, we discuss how temperature, pH, light, and redox state act as external stimuli that reversibly switch between conductive states, yielding ion-selective platforms for sensing and ion sieving. Full article

Controlling cell attachment to substrates with spatiotemporal precision is a key technological foundation in fields such as tissue engineering, cell sorting, and cell–cell interaction analysis. Among existing approaches, azobenzene-based photocontrollable systems offer a promising strategy for the reversible regulation of cell adhesion. However, most conventional systems rely on the intrinsic adhesion capacity of adherent cells. Consequently, although the importance of non-adherent cell types has grown in biomedical research, their dynamic manipulation remains insufficiently explored. In this study, we developed a versatile system to control cell adhesion based on host–guest interactions between an azobenzene–lipid conjugate and a cyclodextrin-functionalized substrate. Using human chronic myelogenous leukemia (K562) cells, we successfully demonstrated photocontrolled adhesion and detachment, confirming the applicability of this system to non-adherent cells. Furthermore, we quantitatively measured the adhesion force and observed an inverse correlation between adhesion efficiency and adhesion force for different PEG linker lengths (2k, 4k, and 8k). This finding demonstrates the critical role of the linker length in effective cell surface modification. In conclusion, the proposed system establishes a photocontrollable adhesion method applicable to non-adherent cells, demonstrating its potential as a versatile technology for broad applications. Full article

Supramolecular nanoparticles offer an efficient strategy to enhance the solubility, stability, and bioavailability of poorly water-soluble therapeutic molecules. In this study, water-dispersible SNPs were successfully prepared from dicarboxyl-bis-pillar[5]arene (H) and cetyltrimethylammonium bromide (CTAB) using a microemulsion method. Dynamic light scattering revealed that the resulting CTAB/H nanoparticles possessed a size distribution centered around 40 nm, a positive surface charge (+15 mV), and exhibited high colloidal stability over three months. ¹H NMR, 2D TOCSY, 2D NOESY, diffusion ordered NMR spectroscopy, and UV-Vis investigations confirmed the inclusion of the CTAB alkyl chain within the pillar[5]arene cavity, supporting the formation of stable supramolecular assemblies capable of efficiently encapsulating the poorly water-soluble flavonol quercetin (Q). The CTAB/H system displayed low cytotoxicity (up to 50 µg/mL) and pronounced antioxidant activity, as evidenced by DPPH, ABTS, and FRAP assays. Quercetin-loaded nanoparticles (CTAB/H/Q) enhanced cellular uptake and exhibited a marked cytoprotective effect against H₂O₂-induced oxidative stress in NIH-3T3 fibroblasts. Full article

The selective removal of trace heteroatomic contaminants from fuel remains a critical challenge for clean combustion and refinery upgrading, particularly due to the chemical stability and structural similarity of sulfur- and nitrogen-containing aromatics. Herein, a surface-engineered graphene oxide aerogel functionalized with cyclodextrin (β-CD-CONH-GO) is developed via covalent grafting to introduce well-defined host–guest recognition sites within a porous framework. Spectroscopic and microscopic characterizations confirm successful functionalization, preserved aerogel morphology, and accessible hybrid interfaces. The removal process for monocyclic, bicyclic, and tricyclic impurities is governed by synergistic molecular inclusion within the cyclodextrin cavity, interfacial hydrogen bonding, and secondary confinement provided by the aerogel porosity. Thus, the β-CD-CONH-GO exhibits efficient adsorption toward representative bicyclic impurities, and the removal performance follows the order of indole > quinoline > benzothiophene. Kinetic analysis demonstrates pseudo-second-order adsorption behavior, indicating chemisorption dominated by cooperative host–guest recognition and hydrogen bonding. It possesses removal selectivity even in mixed systems containing structurally similar aliphatic and aromatic competitors and maintains > 95% efficiency after five regeneration cycles via ethanol extraction, confirming superb durability. This study demonstrates a feasible pathway to design adsorbents for deep fuel refining and highlights cyclodextrin-based graphene hybrid aerogels as promising candidates for separations. Full article

Co-reactants are essential in co-reactant-based electrochemiluminescence (ECL) systems because they generate reactive intermediates that can oxidize or reduce ECL luminophores, thereby driving ECL emission. In the context of ECL, gold nanoclusters (Au NCs) have emerged as innovative luminophores, owing to their tunable electronic structures and excellent biocompatibility. However, their efficiency in ECL applications is often compromised by challenges such as limited excited-state generation and non-radiative losses. To tackle these practical challenges, advanced co-reactant engineering strategies have been developed to improve the performance of Au NCs in ECL systems. This review begins with a brief overview of the mechanisms of ECL. Subsequently, a systematic overview of various co-reactant engineering strategies is presented, including: (1) using innovative co-reactants to replace traditional ones due to their lower toxicity and better biocompatibility; (2) applying co-reaction accelerators to reduce the onset potential and improve the production of reactive intermediates from co-reactants; (3) combining co-reactants with luminophores or creating integrated nanostructure assemblies of co-reactants, co-reaction accelerators, and luminophores to achieve shorter electron transfer paths and reduced energy loss for stable high-intensity ECL emission; (4) utilizing host-guest strategies that encapsulate co-reactants within cavities to stabilize radical intermediates and minimize environmental quenching. This review provides a comprehensive overview of recent developments in co-reactant engineering for Au NCs-based ECL systems, thereby encouraging further exploration and understanding of these systems and expanding their potential applications. Full article

Efficient oxygen transport and accurate anemia diagnostics remain significant medical challenges, as current therapies suffer from stability limitations, immunogenic risks, and inadequate sensitivity. Cucurbiturils (CB[n]), a family of pumpkin-shaped supramolecular macrocycles, present promising solutions due to their rigid architecture, hydrophobic cavities, and strong host–guest binding properties. Functional derivatives such as perhydroxy-cucurbit[5]uril can reversibly bind dioxygen under physiological conditions, highlighting their potential as synthetic hemoglobin substitutes. Additionally, cucurbituril-based probes for Fe³⁺ and folate enable sensitive and selective detection of iron- and folate-deficiency anemia. Biocompatibility assessments in vitro and in vivo indicate low systemic toxicity and acceptable hemocompatibility for homologues such as CB[6], CB[7], and CB[8], though apoptosis, myotoxicity, or cardiotoxicity may occur at elevated concentrations. These data emphasize the need for thorough toxicological evaluation but also demonstrate that cucurbiturils provide a versatile platform for oxygen transport, diagnostic applications, and drug-delivery strategies in anemia management. While their translation to clinical practice is still at an early stage, the structural tunability, stability, and encouraging safety profile of CB[n] macrocycles offer a strong basis for continued biomedical development. Full article

The progression of atherosclerosis (AS) is strongly linked to lipid crystals accumulation caused by cholesterol metabolism disorders and the worsening of the inflammatory microenvironment. Cyclodextrin (CD), characterized by their unique hydrophobic cavity structure, effectively solubilize cholesterol crystals (CCs) through host–guest recognition and act as a multifunctional nanocarrier core, facilitating synergistic therapy that combines pharmaceutical and adjuvant properties. CD-based nano drug delivery systems (CD-NDDS) enable precise targeting of atherosclerotic plaques. By employing synergistic functions (e.g., CCs solubilization, cholesterol efflux promotion via ABCA1/ABCG1 pathways, inflammasome inhibition, and inflammatory microenvironment alleviation), this system provides an effective strategy for AS therapy. Furthermore, CD-NDDS bestows additional pharmaceutical attributes, including enhanced solubility, controlled release, and responsive stimulation. This review begins by elucidating the intrinsic relationship between cholesterol and AS, followed by an examination of the structure-activity relationship governing CD’s cholesterol adsorption. It then explores the construction strategies, structural characteristics, and targeting mechanisms of CD nanodelivery systems in detail. The work systematically assesses CD’s formulation and pharmacological properties in targeted nanodelivery systems for combating AS, integrating drugs and adjuvants. Finally, future research directions are outlined, addressing biocompatibility optimization, targeting efficiency enhancement, and clinical translation challenges to provide a theoretical foundation and technical guidance for precise AS treatment. Full article

A novel artificial light-harvesting system (LHS) for the photooxidation reaction was constructed by the phenyl-bis-naphthyl derivative (PBN) and water-soluble phosphate-pillar[5]arene (WPP5). After host–guest interaction, WPP5 integrated with PBN to form WPP5-PBN amphiphiles, which self-assembled to WPP5-PBN nanoparticles. Based on the aggregate state of PBN in WPP5-PBN nanoparticles, WPP5-PBN nanoparticles emitted a significant yellow fluorescence as energy donors. Due to the yellow fluorescence fully covering the absorption of sulforhodamine 101 (SR101), SR101 was used as energy acceptors and loaded in WPP5-PBN nanoparticles for constructing the WPP5-PBN-SR101 LHS, whose energy transfer efficiency and antenna effect were 66.32% and 22.34. Notably, after the energy of the WPP5-PBN antenna transferred to SR101, more singlet oxygen (¹O₂) production was observed in the WPP5-PBN-SR101 LHS, which was successfully used as a photocatalyst to catalyze the oxidation reaction of 4-methoxythioanisole to 1-methoxy-4-(methylsulfinyl)benzene, imitating the solar energy conversion to chemical energy. Full article

In this study, we review the use of cyclodextrin-based formulations to develop oral tablets of cladribine by enhancing its bioavailability and to improve the solubility and stability of retrometabolic chemical delivery systems (CDSs) in general and estredox, a brain-targeting estradiol-CDS, in particular. Cyclodextrins (CDs), cyclic oligosaccharides that can form host–guest inclusion complexes with a variety of molecules, are widely utilized in pharmaceuticals to increase drug solubility, stability, bioavailability, etc. The stability of the complex depends on how well the guest fits within the cavity of the CD host; a model connecting this to the size of the guest molecules is briefly discussed. Modified CDs, and particularly 2-hydroxypropyl-β-cyclodextrin (HPβCD), provided dramatically increased water solubility and oxidative stability for estredox (estradiol-CDS, E₂-CDS), making its clinical development possible and highlighting the potential of our brain-targeted CDS approach for CNS-targeted delivery with minimal peripheral exposure. A unique HPβCD-based formulation also provided an innovative solution for the development of orally administrable cladribine. The corresponding complex dual CD-complex formed by an amorphous admixture of inclusion- and non-inclusion cladribine–HPβCD complexes led to the development of tablets that provide adequate oral bioavailability for cladribine, as demonstrated in both preclinical and clinical studies. Cladribine–HPβCD tablets (Mavenclad) offer a convenient, effective, and well-tolerated oral therapy for multiple sclerosis, achieving worldwide approval and significant clinical success. Overall, the developments summarized here underscore the importance of tailored cyclodextrin-based approaches for overcoming barriers in drug formulation for compounds with challenging physicochemical properties, and demonstrate the versatility and clinical impact of CD inclusion complexes in modern pharmaceutical development. Full article

This study reports measurements of density, viscosity, and ternary mutual diffusion coefficients (D₁₁, D₁₂, D₂₁, D₂₂) for aqueous solutions containing two antibiotics—sulfamethoxazole (SMX) or trimethoprim (TMP) (component 1)—in the presence of various cyclodextrins (α–CD, β–CD, and γ–CD) (component 2) at 298.15 K. The relative viscosity data were analyzed by fitting to a second-order Jones-Dole equation via a least-squares regression to obtain the viscosity B coefficients. Apparent molar volumes (V_ϕ) were derived from the measured densities (ρ) for SMX and TMP in aqueous media. Furthermore, partial molar volumes of transfer at infinite dilution, ΔV_ϕ⁰, were evaluated to elucidate solute–solvent interactions within the ternary systems investigated. Nonzero ΔV_ϕ⁰ values, positive viscosity B coefficients, and negative cross-diffusion coefficients (D₁₂ and D₂₁), evidencing significant coupled diffusion, collectively indicate strong interactions between the antibiotics and cyclodextrins, consistent with host–guest complex formation. Full article

Background/Objectives: Lipid nanoparticles (LNPs) have demonstrated notable clinical success as advanced drug delivery systems. However, the development of novel covalently bonded ionizable lipids faces substantial technical challenges, as their modification is difficult and they have a high molecular weight. To address this issue, we report the use of host–guest complexes in supramolecular chemistry as functional lipid motifs for constructing LNPs. Methods: Ionizable amine β-cyclodextrin (amine β-CD)-derived host–guest amphiphilic lipid molecules (HGLs) were designed for the construction of multi-stage assembly supramolecular LNPs (MSLNPs). The structure–function relationships and stability of MSLNPs were explored by screening eight types of amine β-CDs and varying the ratio of HGL to yolk phosphatidylcholine. Stability screening and molecular dynamics simulations were performed to clarify the self-assembly mechanisms and optimal formulations, followed by a systematic evaluation of delivery performance. Results: MSLNPs showed a high drug-loading efficiency (> 30%), a rapid-response release in acidic environments, and multi-pathway cellular uptake. In vivo delivery experiments using ethylenediamine β-CD-based MSLNPs in mice revealed no significant immunogenicity, no significant abnormalities in organs/tissues or their functions, a unique biodistribution pattern, and pronounced renal targeting. The successful development of MSLNPs with acidic pH-responsive control, a high delivery efficiency, and renal-targeting properties simplifies LNP preparation. Conclusions: This study offers novel insights into the design of simplified LNPs and the optimization of targeted delivery, with potential applications in renal disease therapy. Full article

A novel inclusion complex of a fluorinated pyrazolopiperidine derivative (5-benzyl-7-(2-fluorobenzylidene)-2,3-bis(2-fluorophenyl)-3,3a,4,5,6,7-hexahydro-2H-pyrazolo [4,3-c]pyridine hydrochloride, PP·HCl) with β-cyclodextrin (PPβCD) was designed, synthesized, and characterized as a potential therapeutic agent for chemotherapy-induced myelosuppression and lymphopenia. Encapsulation of PP within β-cyclodextrin increased aqueous solubility by approximately 3.4-fold and improved dissolution rate by 2.8-fold compared with the free compound. Structural analysis using IR, ^1H/^13C NMR, and TLC confirmed the formation of a stable 1:1 host–guest complex, and the disappearance of free PP signals further supported complete encapsulation. In vivo evaluation in a cyclophosphamide-induced myelosuppression model demonstrated that PPβCD accelerated hematopoietic recovery, restoring leukocyte and erythrocyte counts 35–40% faster than methyluracil, without any signs of systemic toxicity. These findings indicate that β-cyclodextrin complexation significantly enhances solubility, dissolution, and biological efficacy of the pyrazolopiperidine scaffold, supporting further preclinical development of PPβCD as a supportive therapy for chemotherapy-related hematological complications. Full article

Non-covalent and dynamic covalent interactions enable supramolecular systems to function as adaptive platforms in biomedical research, offering novel strategies for precision medicine applications. This review examines five-year developments in supramolecular applications across precision medical domains, including disease diagnosis, bioimaging, targeted drug delivery, tissue engineering, and gene therapy. The review begins by systematically categorizing supramolecular structures into dynamic covalent systems (e.g., disulfide bonds, boronate esters, and hydrazone bonds) and dynamic non-covalent systems (e.g., host–guest interactions, hydrogen-bond networks, metal coordination, and π–π stacking), highlighting current strategies employed to optimize their responsiveness, stability, and targeting efficiency. Representative case studies, such as cyclodextrin-based nanocarriers and metal–organic frameworks (MOFs), are thoroughly analyzed to illustrate how supramolecular systems can enhance precision in drug delivery and improve biocompatibility. Furthermore, this article critically discusses major challenges faced during clinical translation, encompassing structural instability, inadequate specificity of environmental responsiveness, pharmacokinetic and toxicity concerns, and difficulties in scalable manufacturing. Potential future directions to overcome these barriers are proposed, emphasizing biomimetic interface engineering and dynamic crosslinking strategies. Collectively, the continued evolution in structural optimization and functional integration within supramolecular systems holds great promise for achieving personalized diagnostic and therapeutic platforms, thereby accelerating their translation into clinical practice and profoundly shaping the future landscape of precision medicine. Full article